about summary refs log tree commit diff stats
path: root/filters/file-authentication.lua
diff options
context:
space:
mode:
Diffstat (limited to 'filters/file-authentication.lua')
-rw-r--r--filters/file-authentication.lua359
1 files changed, 0 insertions, 359 deletions
diff --git a/filters/file-authentication.lua b/filters/file-authentication.lua deleted file mode 100644 index 0248804..0000000 --- a/filters/file-authentication.lua +++ /dev/null
@@ -1,359 +0,0 @@
1-- This script may be used with the auth-filter.
2--
3-- Requirements:
4-- luaossl
5-- <http://25thandclement.com/~william/projects/luaossl.html>
6-- luaposix
7-- <https://github.com/luaposix/luaposix>
8--
9local sysstat = require("posix.sys.stat")
10local unistd = require("posix.unistd")
11local rand = require("openssl.rand")
12local hmac = require("openssl.hmac")
13
14-- This file should contain a series of lines in the form of:
15-- username1:hash1
16-- username2:hash2
17-- username3:hash3
18-- ...
19-- Hashes can be generated using something like `mkpasswd -m sha-512 -R 300000`.
20-- This file should not be world-readable.
21local users_filename = "/etc/cgit-auth/users"
22
23-- This file should contain a series of lines in the form of:
24-- groupname1:username1,username2,username3,...
25-- ...
26local groups_filename = "/etc/cgit-auth/groups"
27
28-- This file should contain a series of lines in the form of:
29-- reponame1:groupname1,groupname2,groupname3,...
30-- ...
31local repos_filename = "/etc/cgit-auth/repos"
32
33-- Set this to a path this script can write to for storing a persistent
34-- cookie secret, which should not be world-readable.
35local secret_filename = "/var/cache/cgit/auth-secret"
36
37--
38--
39-- Authentication functions follow below. Swap these out if you want different authentication semantics.
40--
41--
42
43-- Looks up a hash for a given user.
44function lookup_hash(user)
45 local line
46 for line in io.lines(users_filename) do
47 local u, h = string.match(line, "(.-):(.+)")
48 if u:lower() == user:lower() then
49 return h
50 end
51 end
52 return nil
53end
54
55-- Looks up users for a given repo.
56function lookup_users(repo)
57 local users = nil
58 local groups = nil
59 local line, group, user
60 for line in io.lines(repos_filename) do
61 local r, g = string.match(line, "(.-):(.+)")
62 if r == repo then
63 groups = { }
64 for group in string.gmatch(g, "([^,]+)") do
65 groups[group:lower()] = true
66 end
67 break
68 end
69 end
70 if groups == nil then
71 return nil
72 end
73 for line in io.lines(groups_filename) do
74 local g, u = string.match(line, "(.-):(.+)")
75 if groups[g:lower()] then
76 if users == nil then
77 users = { }
78 end
79 for user in string.gmatch(u, "([^,]+)") do
80 users[user:lower()] = true
81 end
82 end
83 end
84 return users
85end
86
87
88-- Sets HTTP cookie headers based on post and sets up redirection.
89function authenticate_post()
90 local hash = lookup_hash(post["username"])
91 local redirect = validate_value("redirect", post["redirect"])
92
93 if redirect == nil then
94 not_found()
95 return 0
96 end
97
98 redirect_to(redirect)
99
100 if hash == nil or hash ~= unistd.crypt(post["password"], hash) then
101 set_cookie("cgitauth", "")
102 else
103 -- One week expiration time
104 local username = secure_value("username", post["username"], os.time() + 604800)
105 set_cookie("cgitauth", username)
106 end
107
108 html("\n")
109 return 0
110end
111
112
113-- Returns 1 if the cookie is valid and 0 if it is not.
114function authenticate_cookie()
115 accepted_users = lookup_users(cgit["repo"])
116 if accepted_users == nil then
117 -- We return as valid if the repo is not protected.
118 return 1
119 end
120
121 local username = validate_value("username", get_cookie(http["cookie"], "cgitauth"))
122 if username == nil or not accepted_users[username:lower()] then
123 return 0
124 else
125 return 1
126 end
127end
128
129-- Prints the html for the login form.
130function body()
131 html("<h2>Authentication Required</h2>")
132 html("<form method='post' action='")
133 html_attr(cgit["login"])
134 html("'>")
135 html("<input type='hidden' name='redirect' value='")
136 html_attr(secure_value("redirect", cgit["url"], 0))
137 html("' />")
138 html("<table>")
139 html("<tr><td><label for='username'>Username:</label></td><td><input id='username' name='username' autofocus /></td></tr>")
140 html("<tr><td><label for='password'>Password:</label></td><td><input id='password' name='password' type='password' /></td></tr>")
141 html("<tr><td colspan='2'><input value='Login' type='submit' /></td></tr>")
142 html("</table></form>")
143
144 return 0
145end
146
147
148
149--
150--
151-- Wrapper around filter API, exposing the http table, the cgit table, and the post table to the above functions.
152--
153--
154
155local actions = {}
156actions["authenticate-post"] = authenticate_post
157actions["authenticate-cookie"] = authenticate_cookie
158actions["body"] = body
159
160function filter_open(...)
161 action = actions[select(1, ...)]
162
163 http = {}
164 http["cookie"] = select(2, ...)
165 http["method"] = select(3, ...)
166 http["query"] = select(4, ...)
167 http["referer"] = select(5, ...)
168 http["path"] = select(6, ...)
169 http["host"] = select(7, ...)
170 http["https"] = select(8, ...)
171
172 cgit = {}
173 cgit["repo"] = select(9, ...)
174 cgit["page"] = select(10, ...)
175 cgit["url"] = select(11, ...)
176 cgit["login"] = select(12, ...)
177
178end
179
180function filter_close()
181 return action()
182end
183
184function filter_write(str)
185 post = parse_qs(str)
186end
187
188
189--
190--
191-- Utility functions based on keplerproject/wsapi.
192--
193--
194
195function url_decode(str)
196 if not str then
197 return ""
198 end
199 str = string.gsub(str, "+", " ")
200 str = string.gsub(str, "%%(%x%x)", function(h) return string.char(tonumber(h, 16)) end)
201 str = string.gsub(str, "\r\n", "\n")
202 return str
203end
204
205function url_encode(str)
206 if not str then
207 return ""
208 end
209 str = string.gsub(str, "\n", "\r\n")
210 str = string.gsub(str, "([^%w ])", function(c) return string.format("%%%02X", string.byte(c)) end)
211 str = string.gsub(str, " ", "+")
212 return str
213end
214
215function parse_qs(qs)
216 local tab = {}
217 for key, val in string.gmatch(qs, "([^&=]+)=([^&=]*)&?") do
218 tab[url_decode(key)] = url_decode(val)
219 end
220 return tab
221end
222
223function get_cookie(cookies, name)
224 cookies = string.gsub(";" .. cookies .. ";", "%s*;%s*", ";")
225 return url_decode(string.match(cookies, ";" .. name .. "=(.-);"))
226end
227
228function tohex(b)
229 local x = ""
230 for i = 1, #b do
231 x = x .. string.format("%.2x", string.byte(b, i))
232 end
233 return x
234end
235
236--
237--
238-- Cookie construction and validation helpers.
239--
240--
241
242local secret = nil
243
244-- Loads a secret from a file, creates a secret, or returns one from memory.
245function get_secret()
246 if secret ~= nil then
247 return secret
248 end
249 local secret_file = io.open(secret_filename, "r")
250 if secret_file == nil then
251 local old_umask = sysstat.umask(63)
252 local temporary_filename = secret_filename .. ".tmp." .. tohex(rand.bytes(16))
253 local temporary_file = io.open(temporary_filename, "w")
254 if temporary_file == nil then
255 os.exit(177)
256 end
257 temporary_file:write(tohex(rand.bytes(32)))
258 temporary_file:close()
259 unistd.link(temporary_filename, secret_filename) -- Intentionally fails in the case that another process is doing the same.
260 unistd.unlink(temporary_filename)
261 sysstat.umask(old_umask)
262 secret_file = io.open(secret_filename, "r")
263 end
264 if secret_file == nil then
265 os.exit(177)
266 end
267 secret = secret_file:read()
268 secret_file:close()
269 if secret:len() ~= 64 then
270 os.exit(177)
271 end
272 return secret
273end
274
275-- Returns value of cookie if cookie is valid. Otherwise returns nil.
276function validate_value(expected_field, cookie)
277 local i = 0
278 local value = ""
279 local field = ""
280 local expiration = 0
281 local salt = ""
282 local chmac = ""
283
284 if cookie == nil or cookie:len() < 3 or cookie:sub(1, 1) == "|" then
285 return nil
286 end
287
288 for component in string.gmatch(cookie, "[^|]+") do
289 if i == 0 then
290 field = component
291 elseif i == 1 then
292 value = component
293 elseif i == 2 then
294 expiration = tonumber(component)
295 if expiration == nil then
296 expiration = -1
297 end
298 elseif i == 3 then
299 salt = component
300 elseif i == 4 then
301 chmac = component
302 else
303 break
304 end
305 i = i + 1
306 end
307
308 if chmac == nil or chmac:len() == 0 then
309 return nil
310 end
311
312 -- Lua hashes strings, so these comparisons are time invariant.
313 if chmac ~= tohex(hmac.new(get_secret(), "sha256"):final(field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt)) then
314 return nil
315 end
316
317 if expiration == -1 or (expiration ~= 0 and expiration <= os.time()) then
318 return nil
319 end
320
321 if url_decode(field) ~= expected_field then
322 return nil
323 end
324
325 return url_decode(value)
326end
327
328function secure_value(field, value, expiration)
329 if value == nil or value:len() <= 0 then
330 return ""
331 end
332
333 local authstr = ""
334 local salt = tohex(rand.bytes(16))
335 value = url_encode(value)
336 field = url_encode(field)
337 authstr = field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt
338 authstr = authstr .. "|" .. tohex(hmac.new(get_secret(), "sha256"):final(authstr))
339 return authstr
340end
341
342function set_cookie(cookie, value)
343 html("Set-Cookie: " .. cookie .. "=" .. value .. "; HttpOnly")
344 if http["https"] == "yes" or http["https"] == "on" or http["https"] == "1" then
345 html("; secure")
346 end
347 html("\n")
348end
349
350function redirect_to(url)
351 html("Status: 302 Redirect\n")
352 html("Cache-Control: no-cache, no-store\n")
353 html("Location: " .. url .. "\n")
354end
355
356function not_found()
357 html("Status: 404 Not Found\n")
358 html("Cache-Control: no-cache, no-store\n\n")
359end
© 2022 C. Duckworth. generated by cgit. comments, issues, and patches welcome at < git at acdw dot net >.